The present invention relates to a composition for brazing aluminum or aluminum alloy.
It has been said that torch brazing with a brazing rod is sufficiently applicable to brazing a member made of aluminum or aluminum alloy (hereinafter simply referred to as aluminum alloy) where the aluminum alloy member has a simple shape and requires joints at only a few points.
However, the tubes and fins of a heat exchanger made of aluminum alloy have many joints combined with a complex shape. This complicates the use of torch brazing. In such case, a vacuum brazing method, an inert atmosphere brazing method and a flux brazing method which respectively use a brazing sheet which is clad in advance with a brazing material have been suggested.
Though the above-mentioned brazing method using a brazing sheet is extremely effective for equipment such as a heat exchanger which has a complex shape and many joints, it is wasteful because parts of the device, not necessary for brazing, are clad with brazing material. This unnecessarily increases cost.
In addition, it has been clarified that, since the whole surface is clad with a brazing material, brazing metal erodes to the base metal during heating for brazing thus causing the base metal to be deformed.